title: Vertical ground reaction force-based analysis of powered exoskeleton-assisted walking in persons with motor-complete paraplegia.
abstract: OBJECTIVE
  To use vertical ground reaction force (vGRF) to show the magnitude and pattern of mechanical loading in persons with spinal cord injury (SCI) during powered exoskeleton-assisted walking.
  
  
  METHODS
  A cross-sectional study was performed to analyze vGRF during powered exoskeleton-assisted walking (ReWalk™: Argo Medical Technologies, Inc, Marlborough, MA, USA) compared with vGRF of able-bodied gait.
  
  
  METHODS
  Veterans Affairs Medical Center.
  
  
  METHODS
  Six persons with thoracic motor-complete SCI (T1-T11 AIS A/B) and three age-, height-, weight- and gender-matched able-bodied volunteers participated.
  
  
  METHODS
  SCI participants were trained to ambulate over ground using a ReWalk™. vGRF was recorded using the F-Scan™ system (TekScan, Boston, MA, USA).
  
  
  METHODS
  Peak stance average (PSA) was computed from vGRF and normalized across all participants by percent body weight. Peak vGRF was determined for heel strike, mid-stance, and toe-off. Relative linear impulse and harmonic analysis provided quantitative support for analysis of powered exoskeletal gait.
  
  
  RESULTS
  Participants with motor-complete SCI, ambulating independently with a ReWalk™, demonstrated mechanical loading magnitudes and patterns similar to able-bodied gait. Harmonic analysis of PSA profile by Fourier transform contrasted frequency of stance phase gait components between able-bodied and powered exoskeleton-assisted walking.
  
  
  CONCLUSIONS
  Powered exoskeleton-assisted walking in persons with motor-complete SCI generated vGRF similar in magnitude and pattern to that of able-bodied walking. This suggests the potential for powered exoskeleton-assisted walking to provide a mechanism for mechanical loading to the lower extremities. vGRF profile can be used to examine both magnitude of loading and gait mechanics of powered exoskeleton-assisted walking among participants of different weight, gait speed, and level of assist.
authors.affiliation: James J Peters VA Medical Center, Bronx, NY, USA.
authors.forename: Drew B
authors.initials: DB
authors.lastname: Fineberg
authors.forename: Pierre
authors.initials: P
authors.lastname: Asselin
authors.forename: Noam Y
authors.initials: NY
authors.lastname: Harel
authors.forename: Irina
authors.initials: I
authors.lastname: Agranova-Breyter
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Kornfeld
authors.forename: William A
authors.initials: WA
authors.lastname: Bauman
authors.forename: Ann M
authors.initials: AM
authors.lastname: Spungen
mesh_terms: D000328:Adult; D005260:Female; D005684:Gait; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009989:Orthotic Devices; D010264:Paraplegia / Q000209:etiology / Q000534:rehabilitation*; D016059:Range of Motion, Articular; D012656:Self-Help Devices; D013119:Spinal Cord Injuries / Q000150:complications; D014728:Veterans; D016138:Walking / Q000502:physiology*; D055815:Young Adult